By HARVEY ARATON

August 31, 2014

Prashanth Iyer and Ashwin Verghese were on their way to beginning a day of tennis watching at the Louis Armstrong Stadium when they came upon a commotion around the practice courts at the U.S.T.A. Billie Jean King National Tennis Center.

They were going to check out David Ferrer playing Gilles Simon. But as with most fans at the United States Open’s day sessions, there were options along with sudden realizations.

“I mean, Ferrer’s the No. 5 player in the world,” Verghese, 28, of Philadelphia, said. “But then we heard this was for Roger.”

Welcome to Roger Federer’s prematch hit with his coach, Stefan Edberg, under a broiling late-morning sun, where it was crowded, sticky and a smartphone festival of amateur photographers.

For Federer — product of Switzerland, celebrity of the world — the new bleachers above the practice courts were filled. The new fan runway behind the courts was jammed. The three rows of seating behind the outside fence alongside the courts were taken, and several more unruly rows of folks from behind called out as if they’d known Federer for years as the neighbor from down the block.

“I think many people would rather watch him practice than watch a lot of other guys play a real match,” Verghese said.

His friend Iyer, also 28, of South Brunswick, N.J., said, “I’m already good for the day.”

Never mind that Federer and Edberg, scheduled to hit on Court No. 5, on the side closest to the ground-level fans outside, had moseyed on over to Court No. 4, farther away, but actually providing fans in the upper bleachers a more centralized view.

Hardly a soul closer to Court No. 5 shrugged and left. Nobody complained. In the case of Federer, that apparently would be decidedly uncool.

Mary Beth Jackson, 16, of Pinehurst, N.C., with her father, Wade Jackson, after securing tickets Sunday to attend the Roger Federer match, which he won.

Barton Silverman / The New York Times

“He’s my favorite of all time, my role model,” said Mary Beth Jackson, a 16-year-old tennis player from Pinehurst, N.C., who competes in U.S.T.A.-sanctioned events in the South. “It’s how he acts, how classy he is, how positive he stays.”

Over her blond hair, she had on a blue Federer cap and said she wore it everywhere but to school.

“When I’m playing, I always try to think: What would Roger do?” she said. The response to her rhetorical question: “Not throw the racket.”

Jackson did not have a ticket to Ashe, where Federer would defeat Marcel Granollers of France, 4-6, 6-1, 6-1, 6-1, to reach the fourth round. Several others watching the practice did have entry, but most said their seats were not close to the court and they lamented the vastness of Ashe that made it difficult to get a full appreciation of his balletic movement, his pure strokes.

Federer, 33, is known for his love of the sport and its environment, embracing what others might see as distraction. To reporters last week, he endorsed the new practice access as a good fit with the world’s most boisterous Grand Slam.

“You don’t feel as much privacy and all that stuff,” he said. “But that’s fine. We’re at the U.S. Open.”

For longtime Federer admirers, the courts are a gift from the tennis gods, or in this case the U.S.T.A.

“I saw him at Wimbledon two years ago on my honeymoon,” Matt Green, 30, of Briarcliff, N.Y., said. “But to see it close up is so much better.”

Aras Suziedelis of Severna Park, Md., was watching Federer practice, along with his wife, Dana, and their two children. He said: “I heard John McEnroe say it the other day: ‘There’s nothing like his elegance. It’s like butter.’ ”

His will to play on, at 33, the father of four, has seemed impervious to deflations like last year’s Round of 16 defeat to Tommy Robredo.

“But you just never know,” Dana Suziedelis said. “He could also win something like this and then say, ‘O.K., that’s enough.’ ”

In other words, if you get a chance to see him in a setting like Sunday’s practice, don’t waste it.

Federer fans attend his practices with a variety of gear, though mostly his trademark caps. Ever the tactful capitalist, he told reporters last week that “there is an opportunity for the fan to maybe feel more related to me, more closer to tennis and to me. Then when I do see so many fans showing up with the apparel, I feel closer to it, naturally.”

He does give back. When his warm-up ended abruptly after about a half-hour, nobody raced away to watch Simon’s four-set upset of the fourth-seeded Ferrer, or anyone else. The fans behind the fence, alongside Court 4, were perfectly positioned as Federer spent a good 20 minutes signing caps, balls, programs — pretty much anything put in front of him.

A tournament attendant who was advised by a co-worker not to give his name said that Federer was the only player he had seen at this or last year’s tournament to work the long row of fans, signing as much as he can. Federer did admit last week a preference for his brand gear, which made Mary Beth Jackson stand out as he made his way to the end of the row.

He signed her cap. Later, as Jackson posed for a photo, she was approached by four people on their way out and handed a ticket to Ashe. It was about midway up, a decent view, she said, after watching Federer fall behind, 5-2, in the first set.

Heavy rain suspended the match and ended the day session.

“I wasn’t happy about the score,” she said.

Not to worry. Federer took control after an early start to the night session. Spread about Ashe, the crowd looked smaller than the attendance for his practice.